If you and half your team a not smart of enough for functional programming, along what dimensions is it clearly superior? Just like with single letter variables that only make sense to the author, if functional design only makes sense to one or two people on a team of many, it's clearly inferior.
Functional programming is superior because it leads to more correct programs. Classes of bugs become impossible. With dependent typing, you can prove even more about your programs and mathematically guarantee they're behaving to spec.
Instead, we as an industry choose JavaScript and endless runtime errors, because we don't care about the occasional blowups. We want to move fast, break things, and not have to learn maths.
Note the current state makes business sense: quick and cheap and who cares whether it works well, we'll throw it away soon anyway.
